Pump head mounting



Aprii 10, 195% c. B. MOLLER PUMP HEAD MOUNTING Filed May 31, 1952 ,M wadiii: 0 4 0 ,4 \& Z Z w m WW m I W V. W M

INI'ENTOR. [MUWZW By My United States Patent 9 PUMP HEAD MOUNTINGClifiord B. Muller, Cambridge, Application May 31, 1952, Serial No.298,938

1 Claim. (Cl. 103-150) This invention relates to pumps designed to feedcorrosive liquids, and more particularly to pumping units for suppl'inga stream of liquid at a constant predetermined rate, as for example thechlorination of water flowing in a municipal water main. For easymaintenance, such pump units may comprise a small electric motor, areciprocable rod and operative connections between the motor and rodincluding a train of reduction gearing. This mechanism is mounted in aclosed housing through a wall of which the reciprocable rod projects. Toavoid lubrication difdculties the housing is preferably filled with oil.The electric motor is preferably of the shaded-pole type which willoperate satisfactorily when completely immersed in oil. For reasons ofstrength and economy it is desirable that the main housing be of castmetal. It is essential that the pump itself which is mounted on theoutside of the housing and is operated by the reciprocable rod be soconstructed as to prevent any of the pumped liquid reaching the mainhousing by leal'age or otherwise.

The pump housing, which is attached to the main housing, and the pumpparts are made of noncorrodible material or materials which will beresistant to the liquid to be pumped. For most corrosive liquids suchmaterials as rubber, synthetic resins and stainless steel may besarisfactorily employed.

The pump is preferably of the diaphragm type with the customary checkvalves. The diaphragm and check valves are preferably enclosed in ahousing of transparent plastic to permit inspection thereof while thepump is operating. Since transparent synthetic resins are thermoplasticand soften at temperatures of about 140 F, and since shaded-poleelectric motors have high running temperatures, the transparent housingmembers are separated from the main housing by a member having heatinsulating properties. As hereinafter described, this heat insulatingmember serves not only to protect the transparent pump housing from theheat of the main housing in which the motor is mounted but also protectsthe main housing which is metal from any possible access by thecorrosive liquid which is pumped through the pump housing.

For a more complete understanding of the invention reference may be hadto the following description thereof and to the drawing which shows asectional view of the pump housing and a portion of the main housing,together with the pump itself.

The main housing It) is of a cast aluminum alloy or other suitablematerial and has a circular boss 12 on one side wall to which the pumphousing is secured. The pump housing comprises a circular,corrosion-resistant base member 14 in the form of a shallow cup securedby stainless steel screws 16 to the boss 12. A reciprocable rod 17extends slidably through the boss 12 and a hole in the center of themember 14 to vibrate a diaphragm 20 ice which is mounted on or engagedby the end of the rod. The diaphragm is made of a suitable rubbercompound molded over a reinforcing metal disc 22 in the center of whichis threaded a machine screw 24. The diameter of the disc is nearly equalto the interior diameter of the cup 14. The rubber diaphragm completelycovers the disc 22 except for an exposed face of a central boss 26 whichabuts the outer end face of the rod 17. The end of the rod is drilledand tapped to receive the screw 24 by which the diaphragm is detachablysecured to the rod. The margin 28 of the diaphragm extends radially fromthe rim of the disk 22 and is securely gripped between the annular endface of the base member 1 5 and the rim of a cylindrical block 30 oftransparent plastic material which with the member 14 forms the pumphousing. This block has a central recess at its inner end forming a pumpchamber 32 of which the diaphragm is a vibrating wall. The interiordiameter of the block 3:) at its recessed end is equal to that of themember 14. Inlet and outlet passages 34 and 36 through the block 3%connect the pump chamber with suitable tubes in which are mounted check.valves, the tubes and check valves not being shown on the drawing.Screws 4% of stainless steel or other suitable corrosion-resistantmaterial pass through the margins of the block 36 and diaphragm 28 andinto the base member 14 to secure these parts together. The screws 43,or the holes for them do not extend through the base member 14.Therefore it is impossible for any leakage that will follow along thescrews db to reach, and corrode, the circular boss 12. The rimof themember 1 is preferably but not necessarily recessed to be fitted by themargin 2% of the diaphragm. The diaphragm forms with the member 14 achamber 42 from the bottom of which a vent 44 extends to the outside.

The base member 14 is preferably of a thermosetting synthetic resin ofthe phenol-formaldehyde type which is impervious to corrosive liquids,is to a considerable degree heat resistant, and is an effective heatinsulator. Ordinarily the chamber 42 will be free of the liquid which isbeing pumped by vibration of the diaphragm, but it any such liquidshould get into this chamber either by seepage around the screws 4% orby rupture of the diaphragm, it will drain out through the vent 44. Thebase member 14 thus completely protects the metal housing 1% fromcorrosive liquid and. also protects the transparent housing member 30from the heat generated by the electric motor (not shown) enclosed inthe main housing 143.

I claim:

in combination with a metal housing having a reciprocable pump rodprojecting through a wall thereof, a pump housing comprising acylindrical cup-shaped base member of corrosion-resistant and heatresistant material secured against said wall with said rod projectingtherethrough, a rigid disc having a diameter nearly equal to theinterior diameter of said base member mounted on the projecting end ofsaid rod, 2. rubber diaphragm enveloping said disc and having a marginextending radially from the rim of the disc, a housing block oftransparent plastic material having a centrally recessed end with aninterior diameter equal to that of said base member, and means pressingsaid block against said base member to grip said margin of the diaphragmclose to the edge of the disc and to form with the base member a pumpchamber.

References Cited in the file of this patent UNITED STATES PATENTS2,229,038 Booth Jan. 21, 1941 2,295,774 Corydon Sept. 15, 1942 2,650,545Cornelius Sept. 1, 1953

